1. FIELD OF THE INVENTION
This invention relates to devices for determining the force or speed with which a playing piece associated with a sport is swung, and more particularly to indicators which respond to centrifugal force to provide the desired readings.
2. DESCRIPTION OF THE RELATED ART INCLUDING INFORMATION DISCLOSED UNDER 37 CFR .sctn..sctn.1.97-1.99
More specifically the present invention involves improvements in the centrifugal or swing force indicator illustrated and described in U.S. Pat. No. 4,270,753 dated June 2, 1981, issued to A. Maroth and S. Maroth, and entitled GOLF CLUB SWING INDICATOR, and U.S. Pat. No. 4,363,488 dated Dec. 14, 1982, issued to A. Maroth and S. Maroth, and entitled SWING FORCE INDICATOR FOR PLAYING PIECE OF SPORTS EQUIPMENT.
A prior swing indicator device is shown in U.S. Pat. No. 2,780,098 dated Feb. 5, 1957, issued to A. Maroth, and entitled INDICATING GAUGE RESPONSIVE TO CIRCULAR OR ANGULAR VELOCITY. In this patented construction, a weight is slidable in response to centrifugal force along a turnable, spring-biased shaft carried by a housing mounted on a baseball bat or sports racket, and a spring biased marker member in the housing is engaged by the weight when the latter moves along the shaft, as the result of a swing. The marker member carries a pawl that is cooperable with ratchet teeth disposed on one side of the shaft. Once shifted from a starting position, the marker member remains in an extended position, corresponding to the force of the swing, until the device is reset by momentary turning of the shaft. This was accomplished by depressing a button carried at one end thereof.
U.S. Pat. Nos. 4,270,753 and 4,363,488 identified above show similar devices. The weight member and indicator member of the prior patented gauge have been combined into a single component, and turning of the shaft is accomplished by a manually engageable knob mounted at one end of the shaft. The latter is biased to a position wherein its ratchet teeth are in engagement with the pawl of the weight member. The shaft biasing is effected by a torsion spring connected between the housing and shaft, and surrounding the latter.
While the patented centrifugal force gauges functioned in a generally acceptable manner, they consisted of a relatively large number of individual components. In addition, the assembly of the torsion spring of the devices shown in the two most recent patents was cumbersome, and in some instances the spring or housing cover were susceptible of being jarred loose as a result of an impulse force experienced thereby when the club or racket struck a ball while the gauge was in use.